


Bnha/Haikyuu/Free! Littlespace (COMPLETELY SFW)

by foggy_froggy



Category: Free!, Haikyuu!!, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Age Regression/De-Aging, Fluff, Multi, Non-Sexual Age Play
Language: English
Status: In-Progress
Published: 2021-02-07
Updated: 2021-03-11
Packaged: 2021-03-12 20:21:05
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 7
Words: 6,782
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29266398
Author URL: https://archiveofourown.org/users/foggy_froggy/pseuds/foggy_froggy
Summary: Haikyuu, Free, and Bnha characters using agere as a coping mechanism :)
Relationships: Amajiki Tamaki & Toyomitsu Taishirou | Fat Gum, Hinata Shouyou & Kageyama Tobio, Kozume Kenma & Kuroo Tetsurou, Midoriya Izuku & Yagi Toshinori | All Might, Nanase Haruka & Tachibana Makoto, Other Relationship Tags to Be Added
Comments: 29
Kudos: 64





	1. Request Here!

(Please read my Notes at the bottom!)

Hello, here is where you should request scenarios!

Things I will do:  
\- Babyspace  
\- Pacis/bottles/etc  
\- Non-sexual omo (no messing)  
\- Middle space (older ages like 4,5,6)  
\- Non-verbal littles

Things I will not do:  
\- Anything nsfw  
\- Messing  
\- Violent punishments

A little bit of context + a pair/character is appreciated if you request!

(Ex: MakoHaru where Haru slips at practice and Makoto has to make an excuse for them both to leave so he can take care of him)

It doesn't have to be that specific but a general idea is nice!

If you have any questions don't hesitate to ask! This is a safe place free of judgement :)

**Notes for the Chapter:**

> Hi everyone! This is my first agere fic!
> 
> Things to keep in mind when requesting:  
> \- I have only seen season 1 of bnha, so I can attempt to write characters from later seasons but I can't promise that it'll be in character  
> \- I have only seen Free! Iwatobi and Free! Eternal Summer  
> \- I have only seen 2 seasons of Haikyuu!! but I'm pretty active in that fandom so I'm fairly confident in doing most characters


	2. MakoHaru (Little! Haru)

**Summary for the Chapter:**

> I'm gonna use my example prompt as a starting chapter!
> 
> Prompt: Haru starts slipping during practice and Makoto has to make an excuse so he can get the little home and taken care off.
> 
> Haru's little age: 1-2 (because I'm a sucker for very young littles)
> 
> This is set during Free! Eternal Summer
> 
> ⚠️CW: diaper usage (not in detail, its just cause haru is so little)⚠️

Haru ~~ka~~ Nanase was not having a good day at all. He was falling behind on his studies, because being a third year was much more stressful than he thought, and his schedule had been so disrupted lately with figuring out plans for college and graduation. All of this caused the ravenette to stress out, though of course he didn't show it. 

For the most part, he was fine. He still had the swim club and even though he didn't see them much outside of school, he still had his friends. The straw that broke the camel's back was when he was informed that if he didn't pick his grades up he was in danger of having to give up the swim club. Although Haru held a straight face throughout the talk with his school counselor, he was devastated. His whole future could be jeopardized, along with his mental health, if he was forced to quit swimming. At this point, it was his only escape, considering he hadn't gotten to use his other coping mechanism lately.

Haru had come upon age regression as a way to deal with stress during his second year. Though he seemed generally laid back when it came to swimming, he sometimes got too into his own head, worried he would somehow let the team down. It was becoming so prevalent that even Nagisa noticed something was off, and Makoto was worried sick over his friend. It wasn't fair for them to worry, so he looked into way to deal with stress. After discovering littlespace, he decided to try it, cuddling up with a small dolphin plus Makoto got him and watching some nostalgic movies. It seemed to help, and really clear his mind. Although, the more he slipped and allowed himself to be little, it became apparent that something was missing.. or rather, someone.

Makoto was a little surprised when Haru came to him, asking if he could be his caregiver, but he was nothing short of supportive. He loved taking care of Haru normally, and being his caregiver seemed even better. It became a bit of a routine, and once that got started Haru really settled into his smaller headspace. He slipped pretty young, being around 2 years old at the most, and while he could entertain himself well, he needed constant attention and affection that Makoto was happy to provide. It was nice, and therapeutic for both parties involved.

The problem with having a routine, though, is that it can be a bad thing when it's disrupted. Unfortunately, senior year meant exactly that. It was like second year all over again but worse, with Haru being incredibly stressed and Makoto becoming increasingly worried for him. It all came to a head when practice started, and surprisingly Haru wasn't the first in the pool. When Gou asked what was wrong, she got a shake of Haru's head in response before the freestyle swimmer was diving into the pool, followed by Rei and Nagisa who were eager to get training. Makoto was about to get in when he noticed that Haru was swimming.. very strangely. His movements weren't smooth, instead erratic and struggling. When the boy came to the end of the pool, Makoto waved him down, and thats when he noticed the watery eyes behind Haru's goggles. 

"Haru?? What's wrong?" Makoto whispered, not trying to get anyone else's attention and embarrass the other. 

"I- I can't... 's too hard, Bubba.." Haru sniffed, his voice small and childlike. Makoto felt a tug at his heart because of how sad the boy sounded.

"Hey, is Haru-chan okay?" Piped up Nagisa from a couple lanes over, who had stopped when he saw his two teammates still. This prompted Gou to look over.

"Hm? Is everything okay, you two?" She walked over to the edge of the pool. Haru just stared down at the water, sniffling a little. Makoto knew he had to get the other home, and soon, before he slipped fully. 

"Haru's uh- actually not feeling well, is it okay if I take him home?" Makoto asked, to which Gou nodded, telling them to go and get well so none of the others get sick too.

"Aw, Haru-chan! I hope you feel better soon!" Said the blonde swimmer, to which he got no response. Rei hadn't noticed any of the commotion until Nagisa stopped him, telling him to say his goodbyes and prompting some bickering over Nagisa messing up Rei's rhythm. 

"No worries, we'll see you guys tomorrow, hopefully! Come on, buddy..." Makoto murmured the last part to Haru specifically, helping him out of the pool and walking him to the locker rooms. Haru whined quietly in protest, not wanting to leave the pool regardless of how he was feeling. "I know, I know, how about we get you in a nice bath when we're home instead, hm?" the taller male bargained, helping the little get his shoes on before hoisting him onto his back.

"Mkay.." Haru hummed, laying his head on Makoto's shoulder as he was carried. Makoto was lucky the walk home wasn't too long, and they arrived very soon.

"Hey, don't fall asleep on me, baby, you can nap after bathtime, how's that sound?" Haru was up immediately at the mention of bathtime, and went to the bathroom with Makoto happily. The larger man set him on the sink counter, starting the bath and making sure the water was warm before letting it fill. He got the other's small dolphin toy out and handed it to Haru before beginning to undress the little, setting him in the bath once he was nude. Haru smiled a little, playing with his dolphin and watching it bob around in the water. Meanwhile, Makoto washed the little's hair and skin gently, relaxing the baby until he was slouching in the tub and nearly falling asleep. "Alright, bug, let's get you out and into something comfy." 

Makoto dried Haru off in a fluffy towel, laying the little out on his bed before diapering him up. The caregiver then turned to get Haru's box of little things, prompting the other to whine, not wanting Makoto to leave him. "Bubba nooo.." 

"I'll be right back, buddy, I'm just getting your jammies, I promise." Makoto said, staying in Haru's sights as he got the box from the closet. He was able to avoid a tantrum or an upset by getting out the supplies as quickly as possible, and Haru cooed when he was put in some comfy fish print pajamas. Makoto tickled the other a bit, getting some soft giggles in return. "Do you want a bottle before bed, lovey? Or do you just want to nap?" 

"Seepy..." Haru responded with, sticking his thumb in his mouth. Makoto quickly removed his finger.

"No, no, baby, too many germs." He rummaged around in the box, pulling out a baby blanket, a dolphin stuffie, and a blue pacifier. "Here we are." He put the paci into Haru's waiting mouth and wrapped him up in his blanket before tucking the stuffie between his arms. After Haru was settled and drifting off, Makoto turned off the light in favor of a dolphin nightlight, which lit the room up with a soft blue glow. Makoto then climbed into bed with his little one, smiling at how peaceful he seemed.

Haru couldn't be happier, this was just what he needed.

**Notes for the Chapter:**

> Hope you enjoyed! I'll come up with more ideas until ones are requested! :)


	3. KageHina (Little! Hinata)

**Summary for the Chapter:**

> Request from @YeetMyBeets:
> 
> Hinata is upset over losing a practice game. It's up to Kageyama to help him slip and feel better!

Hinata's head was going a hundred miles a minute, whirring with thoughts as he stepped onto the Activity bus headed back home from Tokyo. Karasuno had a practice match with Nekoma, and while it was fun, Hinata couldn't help but feel bad that they had lost to the other team. He felt like there were so many things he could've done better, and instead of being his normally loud and energetic self on the bus he was very quiet. The small boy's brain was making mountains out of the tiniest of pebbles at this point, thinking about how he could've dived for a certain receive or how he should've hit the ball at a different angle. He started to get overwhelmed quickly and before he knew it his eyes were starting to fill with tears and his headspace was nothing short of fuzzy.

Kageyama was sat next to Hinata as per usual, and was a little perplexed when the middle blocker hadn't annoyed him once a good 20 minutes into the ride. "Hey, dumbass, you tired or something?" He asked quietly, nudging the other with his elbow. Hinata just shrugged, which only confused the black haired boy more. "How do you not know? Whatever, it's just that you're usually full of energy and now you're super quiet, it's freaking me out." He said, huffing a little as he looked at Hinata. "You gonna look at me or am I just gonna keep talking to a brick wall?" He asked, tilting his head to look at the boy's face better.

Hinata turned ever so slightly to look up at Kageyama with a sniffle that was so pitiful it could tug at anyone's heartstrings. "I- I okay.." The smaller said, shaking his head a bit to try and keep himself from sinking into headspace. It was difficult, with his caregiver there and all, and he wanted nothing more than to forget about his worries and snuggle while he wore Kageyama's jacket.

Meanwhile, Kageyama's expression had softened instantly when he saw the look on Hinata's face. He felt awful for not realizing sooner, but knew Hinata wouldn't blame him, after all, reading emotions was something he was still working on. "Is my little one with me today?" Kageyama asked, his mouth quirking up into a half-smile.

He got a shake of a head in response. "I not.. I not little.. I is- am- I'm big.." Hinata said, clearly not wanting to slip somewhere where people besides Kageyama could see him. Despite being a pretty open book, the red head was very private about his littlespace, he was sure his friends would support him if they knew, but he didn't want to risk it. 

"Are you sure you're not little, sweetheart?" Kageyama asked, knowing Hinata was being stubborn. "You know you can slip if you want, everyone else is asleep."

"N-NO! I AM NOT-" Hinata started to shout, only to be told by Ukai to keep it down. This all increased the short boy's tears, and he was nearing a small breakdown at this point. "No, no, no.." He muttered, and Kageyama knew he had to step in.

"Hey.." Kageyama gently touched the other's shoulder, rubbing his thumb in small circles to sooth him. Hinata allowed it, but still felt tense. Kageyama sighed, and removed his hand, prompting a sad look from Hinata. "Calm down, I'm just getting you a couple things to help." The ravenette reached into his bag, pulling out a small lion plushie, a yellow pacifier, and his volleyball jacket. "Here, let's get you settled." Hinata resisted, what if the others saw? Kageyama sensed his apprehensions and responded to them before they could even be voiced, "They're asleep, sweetheart. When we get back I'll carry you and cover you with my jacket so no one sees, sound good?"

"Mm.. mkay.." Hinata murmured, and once he had his comfort items he finally allowed himself to slip. He pressed up against Kageyama, wanting to be close to his caregiver, who he affectionately called 'Papa', at all times. Kageyama didn't mind, he just looked out the window and waited for the ride to be over, that way he could take his baby home and make him happy.

Soon enough, they were back in Miyagi and Kageyama waited for the others to get off before waking his baby up. "Mm.. Papa? I still speepy.." He mumbled, his words jumbled together. 

"I know, but you gotta hop on my back, okay baby?" He got a nod in response, and stood so the little could get onto his back without much trouble. He was lucky their bags weren't too big to carry on his own. Before getting off the bus he pulled his jacket over Hinata's head so he could have his lion and paci in peace without judgement from anyone else. Of course he got a few stares with how he was carrying Hinata, but nothing that wouldn't be lived down. After saying goodbye to his teammates and coaches, he headed to Hinata's home.

Once they arrived at the house Kageyama let them both in using Hinata's key that was in his bag. As he stepped inside he felt movement come from his little one, and took him up to his room before setting him on the bed. "Did you have a nice nap, my little prince?" He asked softly, pulling the jacket off of the little's head.

He got a happy nod in response, Hinata being filled with much more energy now that he was more rested. "Mhm! Wanna play with papa now!" He giggled, making grabby hands at the other. 

"Of course we can play, but how about we get changed first? Those clothes are all icky and sweaty." Hinata seemed to agree, taking off his shirt and his shorts after getting help with his shoes. The caregiver then put the boy into a cat Kigurumi, buttoning it up for him. Hinata snuggled into the comfy clothes, content. Kageyama smiled, "Now, how about I get out your blocks?"

"Yes yes yes!" Hinata squealed, clapping. Kageyama suppressed a chuckle at his baby's behavior and got out the box of toys that resided under the little's bed. He then got out a container of wooden blocks, dumping them out before inviting Hinata to sit with him. The little bounded over, sitting right in Kageyama's lap and nearly knocking his caregiver over. Slowly, the little spelled out small words, getting lots of praise from Kageyama as he did so. He even tried to spell out 'Tobio' even though he got some of the letters mixed up. 

Soon enough, Hinata's stomach was growling and he looked up at Kageyama expectantly. The caregiver gently stood up, picking up Hinata as he did so. "Sounds like someone's hungry, huh? Let's get you some dinner." The taller male quickly picked up the mess of blocks on the floor before bringing Hinata to the kitchen, thankful that his parents and sister were out so Hinata could be openly regressed around the house. Kageyama decided on some dino nuggets and apple slices, the little's favorite meal along with a cup of milk. He set Hinata on the counter while he put the nuggets in the microwave, and the red head swung his legs back and forth as he sat.

The microwave beeped a couple minutes later, "Yay! Nuggies is done!" Hinata shouted, and Kageyama didn't mind. Hinata was happy, he should be allowed to be loud every once and a while. The little one hopped down from the counter and toddled over to his chair, climbing into it and beginning to eat as soon as his food was in front of him, making a small mess that Kageyama was sure to clean up.

After wiping the baby's messy face and eating spot, Kageyama noticed that the little's eyelids were drooping, and he looked quite tired. "I think it's bedtime.." the older said softly, hoisting Hinata up and bringing him back to his room. He set the other into his bed, giving him his lion and paci back from earlier, which soothed the boy into sleep almost immediately. Kageyama turned the lights out and sat at the edge of the bed, petting through orange locks gently. "Goodnight, my sweet prince." Was the last thing Hinata heard before falling into a deep slumber.

**Notes for the Chapter:**

> I hope this is what you wanted! Sorry if it seems a bit rushed I'm still working on my pacing when it comes to writing <3


	4. Tamaki + Fat Gum (Little! Tamaki)

**Summary for the Chapter:**

> Request from @not_a_hufflepuff
> 
> Prompt: While doing paperwork, Tamaki slips from being unnecessarily stressed. Fat Gum realizes what's going on and takes good care of him, providing some entertainment and playtime.

As Tamaki wrote down more details on his paperwork, he could feel his mind becoming almost.. drowsy. Yet he wasn't tired. It was like the little gears in his head were slowing down, and it was becoming increasingly hard to write. The boy did his best to not bring attention to himself, especially not from Fat Gum, who was working across from him at the table. Tamaki blinked, shaking his head a little so he could keep it together. He refused to believe that he was slipping _now_ of all times. Usually he could wait until there wasn't so much work to do, or when it was a quiet day in the office. Well, he supposed at least it was just him and Toyomitsu here, he'd be 10x more mortified if it was anyone else.

Subconsciously, as Tamaki forced himself to write, his shirt found its way between his teeth, and he was chewing the fabric gently in a manner that was soothing to his mind, and soon enough he stopped working altogether. Unfortunately (very fortunately) for the shy boy, the other in the room took notice. "Hey, you okay there, Tamaki?" He asked, looking up at the younger hero.

"Hm? Oh- y-yes. I'm fine." He wished to just shove his face into a corner, especially now that Toyomitsu caught him chewing on his shirt like an idle child with nothing better to do. However, if he did find a wall to find peace in, the other would certainly not buy that he was 'fine' and would pry more. Tamaki definitely didn't want that. Once again he started to write, but things were so difficult. His motor skills were off, as he was so close to slipping, and he found himself trying to write the same sentence five times before he finally became fed up. Before he knew it, teardrops littered the paper on the table, and he sniffles enough to get Fat Gum's immediate attention.

"Tamaki? What's- oh, I see now..." The elder said, standing and walking over to the younger boy, who had his head low from embarrassment. No matter how much he trusted the hero, he was still flustered when he initially slipped in front of him. "I think I have a little Maki on my hands today, is that right?" The younger shook his head, too embarrassed to admit it, "Hm? I guess you don't want to play, then, my mistake.." Toyomitsu said, smiling knowingly. The little's head immediately shot up and he shook his head, letting himself slip fully.

"No no! Wanna play.." He said quickly, trying to amend the situation. He even stood up, walking over to the small cabinet where he kept some of his little items and toys. He pulled out some large cars clearly made for children, along with some stuffed dolls and his blankie. Tamaki always had his blue blankie with him when he was in his headspace, the hero had gotten it years ago when he was a newborn, and had been attached to it ever since, especially when he was regressed. He rubbed the soft fabric against his cheek before bringing the items over, sitting on the floor and reaching out for the other male to let him know that he wanted to be with him. The older smiled, happy that Tamaki was out of his shell some in littlespace. 

"Well what do we have here? These are some cool looking toys, bunny!" Tamaki flushed at the praise, giving a car to Fat Gum and driving another around, making small 'vroom' noises. The older hero responded with noises of his own, and the little couldn't help but giggle. After a while, though, Tamaki got bored and it was obvious to his caregiver. "Hey, bug, why don't we play something else?"

"Somefin else?" Tamaki asked curiously, blinking up at the other. "Hm.. hero and vi- vill- bad guys!" The little decided, having trouble with the word 'villains.'

"That's a good idea, Maki, my smart boy. Why don't you be the hero? I'll be the villain, and-" He grabbed one of Tamaki's dolls "-this is my hostage, you better save them!" Tamaki gave a look of determination before tying his blanket around his neck messily.

"I gots a cape like a real hero! You is no match for me!" He said, determined. Tamaki then ran over to Fat Gum, jumping to try and get the toy from his hands. The other easily avoided it, though.

"Oh no, I'm under attack! Good thing my super power is.. tickles!" The older exclaimed before picking the little up and lightly tickling his sides. Tamaki squealed with laughter until happy tears were in his eyes. That's when the 'villain' decided to let up, "No.. it seems my power is all out for now!" 

"I've got you villa [villain]! You is no match for me!" Tamaki grabbed the doll from Fat Gum with a smile, "I have saved the civan [civilian]!" If Tamaki pronounced some words wrong, Fat Gum surely didn't say anything, just enjoying his little one's happiness. 

"You did it, bug! You're the bravest little hero ever!" He scooped the boy up, giving him a hug and a kiss on the forehead.

"You think Imma be a real hero one day, Dada?"

"Of course you will, Tamaki.. I'm sure of it."

All Tamaki could do was blush, feeling so wonderfully loved.

**Notes for the Chapter:**

> I hope you enjoyed! <3


	5. Aizawa & Bakugou (Little! Bakugou)

**Summary for the Chapter:**

> Request from anon!
> 
> Prompt: Little Katsuki and Dadzawa!
> 
> Katsuki's little age range: 2-3
> 
> CW: light swearing, just a couple choice words from Bakugou while he's big

Katsuki paled when he got his paper back, the test covered in red marker and a large less than desirable number as his score. This was the third assignment in a row that he nearly failed. He knew it was bringing his average down, and that was enough to make him incredibly angry. Enough so that when Kaminari looked over curiously to compare scores, and made a comment about how the test must've been really tough, Bakugou snapped.

"QUIET YOU DAMN EXTRA, WHY DON'T YOU GO SHORT-CIRCUIT YOURSELF FOR THE THIRD TIME TODAY SO WE DON'T HAVE TO HEAR YOUR ANNOYING ASS VOICE!" He shouted, his palms crackling with small sparks threatening to blow. This caught everyone's attention. It was pretty normal for Bakugou to have outbursts, but he had been working on it, and this time things seemed to be teetering on the edge of too personal.

Denki put his hands up in defense. "My bad, dude, jeez.." He murmured, going back to minding his business.

"What's got you all up in arms, Bakubro?" Kirishima asked, leaning over. Once he noticed the paper, he spoke again, "Ohh.. don't sweat it, dude, I didn't do so good either."

He barely got his words out before Bakugou yelled at the red-head too, "WELL YEAH, THAT'S NORMAL FOR YOU, DUMBASS! But some of us, mainly me, have an IQ that's ABOVE ROOM TEMPERATURE." Katsuki huffed, looking back to his grade. 

"Woah, not cool, man. It's one grade, get over yourself." Kirishima replied, walking over to sit beside Mina before the other could say anything in return.

"Bakugou, I'd like you to see me after class, please." Came a voice from the front of the room. Aizawa noticed something was off with Bakugou. To most others it seemed like he was just frustrated with his test score, but the teacher knew it was more than that. He sensed something was off when the blonde nearly failed a quiz a week ago that even Kaminari had passed with flying colors, which was odd considering the electric blonde wasn't a good test taker and Katsuki had proven himself the opposite time and time again. 

"Tch, whatever.." Katsuki muttered, laying his head down on his desk. Aizawa was right in his thought process, of course. Bakugou wasn't usually one to get upset to the point of trying to make things personal, especially over one grade. The poor kid had been stressed out of his mind lately, and had barely been getting any sleep, relying on pure willpower and adrenaline to get through the day. On top of that, he had been making so many simple mistakes in class, and it was costing him. The boy barely had enough time to eat, let alone have time to relieve his stress. The small plush kept in his bookbag and the glasses of milk at lunch just weren't cutting it, they surely weren't a substitute for littlespace. The more Katsuki thought about his smaller headspace, the more he wanted to just slip, regardless of who was present. Of course, his pride wouldn't let him do such, so he would just have to wait until he got back to the dorms. Regardless of what he wanted, though, his thoughts started putting him into an in between headspace of sorts, and he craved more than ever for class to be over.

Soon enough, the bell rang and students filed out, leaving only Katsuki and Aizawa in the room. The older spoke up first. "Bakugou, can you close the door then pull up a chair to my desk, please?" Katsuki just nodded, not wanting to speak just in case he sounded small. He grabbed a chair and dragged it over to Aizawa's desk, sitting down and looking at his own feet. "Thank you. Now, would you like to tell me what's going on?" He got a shake of the head, "Alright, let me rephrase that. Tell me what's bothering you. One of my best students is failing or nearly failing assignments, and I know those outbursts today weren't over something as trivial as a test score."

Bakugou shook his head again, "No, no.. don't wanna.." He wanted to cry when he heard how childish his voice sounded, but settled on just crossing his arms with a huff, giving in to his littlespace at this point.

"Hm.." Aizawa's brows furrowed, "Bakugou, look at me." It took the blonde a minute but he did as he was asked, looking up at the older man with a pout. It didn't take long for Aizawa to put two and two together, he knew of all types of coping mechanisms for heroes, after all, and age regression was one of them. He was fairly sure thats what was happening to Bakugou, and while it was a little surprising, he couldn't fault the boy for having a healthy coping mechanism. "Katsuki.. can you tell me how old you are?"

The little's pout softened, and he thought for a moment before holding up two fingers, "This many!" He said, his voice high pitched and softer than normal. 

Aizawa nodded, a small smile on his lips, "Ah, I see, do you remember the last time you were that many years old?" After getting a blink as an answer, Aizawa knew it was far too long ago. ' _I bet that's why he was so upset, a lot's been going on recently'_ he thought, before opening a drawer in his desk. He kept small toys in there, as some of his friends used regression to cope and he always wanted to be prepared. "I think I have a couple fun toys for you." The man said before pulling out an All Might plush and a small wooden puzzle. The little one let out a small 'ooo' and reached out for the toys, bouncing in his chair a bit. "Alright, buddy, why don't we sit on the floor so you can do your puzzle?" 

"Yeah yeah! Puzzle!" Katsuki clapped, quickly getting onto the floor with Aizawa following suit. The older set the puzzle frame down and took the pieces out so Katsuki could put them back. He then handed the little the all might stuffie, which Katsuki started clinging to immediately. It took a bit, but Bakugou eventually solved the puzzle, and clapped for himself, "Look! 'Zawa! I dids it!" He exclaimed.

"I see, you're such a smart boy, Katsuki." Aizawa praised, ruffling the little one's hair which pulled a giggle out of the younger, although it was directly followed by a yawn. That's when the teacher fully noticed his student's eyes, and how tired they looked, bags matching his own starting to form. "Alright, buddy, I think someone needs a nap."

"Nooo.." Whined Katsuki, though he was clearly tired, one hand rubbing his eye.

"Yes, Katsuki. You'll feel much better after, and then we can play some more, okay?" He got a sleepy nod in response, to which he smiled and picked up Katsuki. "You can even sleep here." Aizawa said, bringing the boy over to his sleeping bag. He had nearly got the boy tucked in when Katsuki whined again.

"Wait! Kitty's in my bag, she'll be lonely!" He exclaimed, sounding very distressed.

"Hey, calm down, I'll get her right now, okay?" Aizawa got up and rummaged around Bakugou's bag just a bit until he found the soft white cat, tinged a little grey from how well loved it was. He brought the toy over to Katsuki. "Here we are." He tucked it into the boy's arms and zipped up the sleeping back before turning off the classroom lights, leaving his desk lamp on to give the room a warm glow. "Sweet dreams, problem child.." 

Katsuki was asleep before Aizawa could even finish the phrase.

**Notes for the Chapter:**

> I hope you enjoyed it! <3


	6. Deku + All Might (Little! Izuku)

**Summary for the Chapter:**

> Request from @Cigarettes_and_GIngerAle
> 
> Deku is training with All Might when he slips. All Might is confused but accepting and more than willing to take care of him!

Midoriya had definitely had better days before, that's for sure. On top of being a few minutes late to class this morning, he got a less than satisfactory grade on a test and didn't get to finish his lunch during lunch time. All of these things combined made Deku long to slip into a smaller headspace and make the outside world go away for a while. He forced himself to be big, though. After all, he had something to look forward to, he was training with All Might today! Surely that would make everything right.

Unfortunately, Izuku was wrong about that. On the way to one of the training grounds he fell in front of some classmates, causing him to get hurt and be laughed at. This normally wouldn't upset him, but all the bad things happening today were piling up, and more than ever he just wanted to curl up in bed with his stuffed bunny and an old All Might cartoon. However, he was determined not to miss this training session, he needed to work hard if he wanted to reach his full potential with his quirk, after all. He couldn't do that if he put off training for something as trivial as his littlespace. He just blinked back the tears that were forming and continued on, finally reaching the place he'd been waiting for all day now.

The young male stepped inside the locker rooms outside the training grounds and opened his back, his small smile that had formed disappearing as soon as he realized.. he forgot his costume. He didn't have his gym uniform in his bag either. The greenette had to take a deep breath to calm himself. This was fine, he just made a small mistake. This could just be practice for if anything like this happened while he was on the job. He had to be able to fight in any clothing, right? Even if it was his school uniform.

After discarding his tie and blazer, figuring it would limit his movement, he walked out into the training area, please to find All Might already there.

"Ah, Young Midoriya!" The older exclaimed, "It's been quite some time, I'm looking forward to training with you today. But... where's your costume?" He asked in genuine confusion. Izuku usually wore his hero costume any chance he could get.

"I.. um- I just wanted to train in something different! After all, what if something happens while I'm in class without my costume on me?" The boy quickly made up an excuse. "I think it'll be good for me!"

All Might was a little confused, but his furrowed brow was quickly replaced with a signature smile, "Good thinking, my boy! Let's get started, shall we. First, let's warm up."

The two stretched before the older began to show the younger a new, yet simple move that he could try. Just to add a bit of variety in his fighting style. It also didn't put too much strain on the poor boy's body. After demonstrating, All Might guided Deku to do it himself. However, it seemed the small boy was having trouble.

"Let's try changing the angle of your arm, that might help!" All might said, adjusting the boy. Yet as soon as he tried to destroy the dummy in front of him, he cried out in pain. He couldn't believe himself, he'd been at it for at least half an hour and still couldn't do something All Might deemed simple. He was a failure of a hero, he couldn't even use his quirk in a simple way, he couldn't even fight without hurting himself through his own doing. Izuku was in his own head so much that he didn't even realize he was crying until it happened.

The older hero coughed, going into his smaller form when he saw tears falling onto the dirt below them. He knew his heir was a bit emotional at times, but this seemed very different. "Hey, hey, its nothing to fret over, we could try something else-"

"N-no!" Deku exclaimed, rather childishly. This was the straw that broke the camel's back so it seemed, and the boy couldn't control how fast he was falling into littlespace. "C-can't! Bad, bad!" He shook his head quickly, back and forth.

Yagi was a little stunned, why was Midoriya acting so.. odd? He was behaving like a child, which was out of character for him. Sure, the kid was very in touch with his emotions, but he remained pretty mature in most situations. "Midoriya, please, calm down, what's wrong?" He hated seeing the other sad, and wanted to help, he just didn't know how.

"E-everything!" The boy cried, slumping until he was sitting on the ground, his thumb absent-mindedly going into his mouth.

This served to only further confuse the other, until he remembered an instance where one of his coworkers was acting the same way around he and Aizawa. The black haired man knew just what to do, then explained to Toshinori after the other was calmed down. It was called age... regression! Yes, that's it. He told him that their friend used it to cope with stress, and that would make sense, Midoriya seemed very distraught.

"Hey, kid, how um.. old are you?" He asked cautiously. If he got the normal answer of Deku's actual age, he'd know this was just a small meltdown, but if he got something different...

"I- um.." Izuku cautiously held up three fingers, "This.." He said quietly, and Yagi knew what he had to do.

"Alright, little one, thank you for telling me. Let's get you back to your dorm, we can pick up training later, okay?" This earned a whine from the younger, "You've done enough today, Midoriya, you did very good, you deserve some rest." He replied, trying to affirm that Izuku did nothing wrong and this was for the best. He picked up the boy gently, to which the green haired boy buried his face in his shoulder, seemingly a bit shy. He then walked out with him, being sure to grab his bag on the way out. It was around dinnertime, so luckily the halls were empty and he didn't have to worry about any concerned stares. He walked back to the dorms and went to Midoriya's, setting the small boy down on his bed.

Izuku hummed, immediately reaching up for All Might once he was put down. The little one could get very clingy, even if he slipped to an older age. "No leave.."

The older gave him a smile. "I'm not going anywhere. I'm just gonna get you some comfy clothes, okay?" This seemed to calm the other down, and Toshinori made quick work of going through the other's drawers to get out some clothes. He quickly found some soft sweatpants and a comfy looking shirt. While he was searching he also came across a stuffed bunny that he figured the little one would want. 

He walked back over to the bed, handing the bunny to Izuku, "Look what I found, little one!" Izuku was instantly smiling, taking the bunny and hugging it close to his chest

"Bun bun!" He exclaimed, running his hands over the soft fur.

"That's right, buddy. Now let's get you changed." Izuku was very cooperative, letting the other unbutton his shirt and slip off his school pants, only for them to be replaced with comfier clothes. "There we go." The younger let out a yawn. "Alright, why don't you lay down for a while, then you can eat when you wake up?"

The younger hummed in reply, too tired to do much else, and reached out for the other once he was tucked under the covers with his bunny. "Mm.. story?" He asked quietly, looking up at Yagi with pleading eyes.

"Of course, Midoriya. Anything for you." And with that, Toshinori began to tell a tale of heroes and villains, where the heroes (who were a lot like Deku and All Might) emerged victorious.

**Notes for the Chapter:**

> I hope you enjoyed this! <3


	7. Little! Kuroo + CG! Kenma

**Summary for the Chapter:**

> Kuroo and Kenma set aside some time after a big game so they can relax together.
> 
> (I imagine Kuroo to be a little older, like a 4-5 age)

Kuroo was practically bouncing on the walk home, and normally Kenma would be slightly annoyed at that, but today was different. The extra energy wasn't unwelcome, and he knew teasing him for something this harmless would leave him with a very fussy little on his hands. 

The black haired boy had been waiting for this for days now, just some time alone with Kenma when he could regress and play with the other happily. He was practically in his littlespace when the two reached the shorter male's house. His parents were out of town so he felt so safe and free of judgement that he couldn't help but speed towards where his little items were kept as soon as he got in the door.

Immediately the blonde was chasing after a little boy, who was dumping out a tub of blocks and cars once he reached his room. "Kuroo, sweetie, don't go running around in the house... Running is for outside, remember?"

Kuroo frowned, but it was brief. "Oh.. okay! I sorry." He said quickly, starting to stack up the large wooden blocks and make a little town. The cars were arranged in a neat line out of the way ('so they stay safe cause of the um.. construction!') and he was happy to entertain himself for a bit. Once he was ready to actually play with the cars, however. He was tugging his caregiver over to play. "Papa! papa! Play cars with me!" He handed Kenma a car and immediately started crawling around with his own car. 

Kenma joined in, indulging his little one for a while before Kuroo's stomach let out a loud growl. "Sounds like someone's hungry... let's go get you some dinner. Time to clean up."

"Aww..." Kuroo whined. He wanted to keep playing! Despite this, he did what he was told without any more hesitation, putting his toys back where they belong.

"Very good, baby. I think you've earned a pudding cup for dessert!" That brightened Kuroo's attitude immediately, and he beamed as he ran over and hugged onto Kenma, nearly knocking the boy over. "Mpf! Alright, alright.." The blonde hugged his little one back, rubbing circles between his shoulders. He then pulled back and grabbed his hand. "Let's go get something to eat."

The two walked into the kitchen together, and once Kuroo was seated the caregiver got out a Kid Cuisine, one of the little's favorite things to eat when he was feeling small. After heating it up, he served it to the little one. "Here we go! Eat up, precious."

Kuroo dug into his food, and practically licked the plate clean in no time at all. "All done! Puddin now?" He asked, looking up at Kenma with a smile.

The caregiver returned the smile and got a vanilla pudding cup from the fridge. "Yes, you get your pudding now." He gave him a spoon and Kuroo savored the sweet treat, though not without making a mess.

"All done!" He exclaimed yet again, pudding on his face and shirt.

Kenma just chuckled, "Alright, lovey. Now let's get you cleaned up..."

**Notes for the Chapter:**

> Hope you enjoyed! <3
> 
> (if you requested something I promise I'll get to it, but if it's from a later season I may need to read up on some characters)


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